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<td ><a href="../qtdoc/index.html">Qt 5.12</a></td><td ><a href="qtquick-index.html">Qt Quick 模块</a></td><td ><a href="qtquick-qmlmodule.html">QML类型</a></td><td >PropertyAction QML 类型</td></tr></table><table class="buildversion"><tr>
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<h3><a name="toc">目录</a></h3>
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<li class="level1"><a href="#properties">属性</a></li>
<li class="level1"><a href="#details">详细信息</a></li>
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<h1 class="title">PropertyAction QML 类型</h1>
<span class="subtitle"></span>
<!-- $$$PropertyAction-brief -->
<p>Specifies immediate property changes during animation. <a href="#details">更多...</a></p>
<!-- @@@PropertyAction -->
<div class="table"><table class="alignedsummary">
<tr><td class="memItemLeft rightAlign topAlign"> 导入语句：</td><td class="memItemRight bottomAlign"> import QtQuick 2.12</td></tr><tr><td class="memItemLeft rightAlign topAlign">继承自：</td><td class="memItemRight bottomAlign"> <p><a href="qml-qtquick-animation.html">Animation</a></p>
</td></tr></table></div><ul>
<li><a href="qml-qtquick-propertyaction-members.html">所有成员的列表，包括继承成员</a></li>
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<a name="properties"></a>
<h2 id="properties">属性</h2>
<ul>
<li class="fn"><b><b><a href="qml-qtquick-propertyaction.html#exclude-prop">exclude</a></b></b> : list&lt;Object&gt;</li>
<li class="fn"><b><b><a href="qml-qtquick-propertyaction.html#properties-prop">properties</a></b></b> : string</li>
<li class="fn"><b><b><a href="qml-qtquick-propertyaction.html#property-prop">property</a></b></b> : string</li>
<li class="fn"><b><b><a href="qml-qtquick-propertyaction.html#target-prop">target</a></b></b> : Object</li>
<li class="fn"><b><b><a href="qml-qtquick-propertyaction.html#targets-prop">targets</a></b></b> : list&lt;Object&gt;</li>
<li class="fn"><b><b><a href="qml-qtquick-propertyaction.html#value-prop">value</a></b></b> : any</li>
</ul>
<!-- $$$PropertyAction-description -->
<a name="details"></a>
<h2 id="details">详细信息</h2>
<p><a href="qml-qtquick-propertyaction.html">PropertyAction</a> is used to specify an immediate property change during an animation. The property change is not animated.</p>
<p>It is useful for setting non-animated property values during an animation.</p>
<p>For example, here is a <a href="qml-qtquick-sequentialanimation.html">SequentialAnimation</a> that sets the image's <a href="qml-qtquick-item.html#opacity-prop">opacity</a> property to <code>.5</code>, animates the width of the image, then sets <a href="qml-qtquick-item.html#opacity-prop">opacity</a> back to <code>1</code>:</p>
<pre class="qml">

  <span class="type"><a href="qml-qtquick-sequentialanimation.html">SequentialAnimation</a></span> {
      <span class="type"><a href="qml-qtquick-propertyaction.html">PropertyAction</a></span> { <span class="name">target</span>: <span class="name">img</span>; <span class="name">property</span>: <span class="string">&quot;opacity&quot;</span>; <span class="name">value</span>: <span class="number">.5</span> }
      <span class="type"><a href="qml-qtquick-numberanimation.html">NumberAnimation</a></span> { <span class="name">target</span>: <span class="name">img</span>; <span class="name">property</span>: <span class="string">&quot;width&quot;</span>; <span class="name">to</span>: <span class="number">300</span>; <span class="name">duration</span>: <span class="number">1000</span> }
      <span class="type"><a href="qml-qtquick-propertyaction.html">PropertyAction</a></span> { <span class="name">target</span>: <span class="name">img</span>; <span class="name">property</span>: <span class="string">&quot;opacity&quot;</span>; <span class="name">value</span>: <span class="number">1</span> }
  }

</pre>
<p><a href="qml-qtquick-propertyaction.html">PropertyAction</a> is also useful for setting the exact point at which a property change should occur during a <a href="qmlexampletoggleswitch.html#transition">Transition</a>. For example, if <a href="qml-qtquick-propertychanges.html">PropertyChanges</a> was used in a <a href="qml-qtquick-state.html">State</a> to rotate an item around a particular <a href="qml-qtquick-item.html#transformOrigin-prop">transformOrigin</a>, it might be implemented like this:</p>
<pre class="qml">

  <span class="type"><a href="qml-qtquick-item.html">Item</a></span> {
      <span class="name">width</span>: <span class="number">400</span>; <span class="name">height</span>: <span class="number">400</span>

      <span class="type"><a href="qml-qtquick-rectangle.html">Rectangle</a></span> {
          <span class="name">id</span>: <span class="name">rect</span>
          <span class="name">width</span>: <span class="number">200</span>; <span class="name">height</span>: <span class="number">100</span>
          <span class="name">color</span>: <span class="string">&quot;red&quot;</span>

          <span class="name">states</span>: <span class="name">State</span> {
              <span class="name">name</span>: <span class="string">&quot;rotated&quot;</span>
              <span class="type"><a href="qml-qtquick-propertychanges.html">PropertyChanges</a></span> { <span class="name">target</span>: <span class="name">rect</span>; <span class="name">rotation</span>: <span class="number">180</span>; <span class="name">transformOrigin</span>: <span class="name">Item</span>.<span class="name">BottomRight</span> }
          }

          <span class="name">transitions</span>: <span class="name">Transition</span> {
              <span class="type"><a href="qml-qtquick-rotationanimation.html">RotationAnimation</a></span> { <span class="name">duration</span>: <span class="number">1000</span>; <span class="name">direction</span>: <span class="name">RotationAnimation</span>.<span class="name">Counterclockwise</span> }
          }

          <span class="type"><a href="qml-qtquick-mousearea.html">MouseArea</a></span> {
              <span class="name">anchors</span>.fill: <span class="name">parent</span>
              <span class="name">onClicked</span>: <span class="name">rect</span>.<span class="name">state</span> <span class="operator">=</span> <span class="string">&quot;rotated&quot;</span>
          }
      }
  }

</pre>
<p>However, with this code, the <code>transformOrigin</code> is not set until <i>after</i> the animation, as a <a href="qml-qtquick-state.html">State</a> is taken to define the values at the <i>end</i> of a transition. The animation would rotate at the default <code>transformOrigin</code>, then jump to <code>Item.BottomRight</code>. To fix this, insert a <a href="qml-qtquick-propertyaction.html">PropertyAction</a> before the <a href="qml-qtquick-rotationanimation.html">RotationAnimation</a> begins:</p>
<pre class="qml">

  <span class="name">transitions</span>: <span class="name">Transition</span> {
      <span class="type"><a href="qml-qtquick-sequentialanimation.html">SequentialAnimation</a></span> {
          <span class="type"><a href="qml-qtquick-propertyaction.html">PropertyAction</a></span> { <span class="name">target</span>: <span class="name">rect</span>; <span class="name">property</span>: <span class="string">&quot;transformOrigin&quot;</span> }
          <span class="type"><a href="qml-qtquick-rotationanimation.html">RotationAnimation</a></span> { <span class="name">duration</span>: <span class="number">1000</span>; <span class="name">direction</span>: <span class="name">RotationAnimation</span>.<span class="name">Counterclockwise</span> }
      }
  }

</pre>
<p>This immediately sets the <code>transformOrigin</code> property to the value defined in the end state of the <a href="qmlexampletoggleswitch.html#transition">Transition</a> (i.e&#x2e; the value defined in the <a href="qml-qtquick-propertyaction.html">PropertyAction</a> object) so that the rotation animation begins with the correct transform origin.</p>
<p><b>请参考 </b><a href="qtquick-statesanimations-animations.html">Animation 和 Transitions in Qt Quick</a> 和 <a href="../qtqml/qtqml-index.html">Qt QML</a>。</p>
<!-- @@@PropertyAction -->
<h2>属性文档</h2>
<!-- $$$exclude -->
<div class="qmlitem"><div class="qmlproto">
<div class="table"><table class="qmlname">
<tr valign="top" class="odd" id="exclude-prop">
<td class="tblQmlPropNode"><p>
<a name="exclude-prop"></a><span class="name">exclude</span> : <span class="type"><a href="../qtqml/qml-list.html">list</a></span>&lt;<span class="type">Object</span>&gt;</p></td></tr>
</table></div>
</div><div class="qmldoc"><p>This property holds the objects that should not be affected by this action.</p>
<p><b>请参考 </b><a href="qml-qtquick-propertyaction.html#targets-prop">targets</a>。</p>
</div></div><!-- @@@exclude -->
<br/>
<!-- $$$properties -->
<div class="qmlitem"><div class="qmlproto">
<div class="table"><table class="qmlname">
<tr valign="top" class="odd" id="properties-prop">
<td class="tblQmlPropNode"><p>
<a name="properties-prop"></a><span class="name">properties</span> : <span class="type"><a href="../qtqml/qml-string.html">string</a></span></p></td></tr>
</table></div>
</div><div class="qmldoc"><p>These properties determine the items and their properties that are affected by this action.</p>
<p>The details of how these properties are interpreted in different situations is covered in the <a href="qml-qtquick-propertyanimation.html#properties-prop">corresponding</a> <a href="qtquick-animation-example.html#propertyanimation">PropertyAnimation</a> documentation.</p>
<p><b>请参考 </b><a href="qml-qtquick-propertyaction.html#exclude-prop">exclude</a>。</p>
</div></div><!-- @@@properties -->
<br/>
<!-- $$$property -->
<div class="qmlitem"><div class="qmlproto">
<div class="table"><table class="qmlname">
<tr valign="top" class="odd" id="property-prop">
<td class="tblQmlPropNode"><p>
<a name="property-prop"></a><span class="name">property</span> : <span class="type"><a href="../qtqml/qml-string.html">string</a></span></p></td></tr>
</table></div>
</div><div class="qmldoc"><p>These properties determine the items and their properties that are affected by this action.</p>
<p>The details of how these properties are interpreted in different situations is covered in the <a href="qml-qtquick-propertyanimation.html#properties-prop">corresponding</a> <a href="qtquick-animation-example.html#propertyanimation">PropertyAnimation</a> documentation.</p>
<p><b>请参考 </b><a href="qml-qtquick-propertyaction.html#exclude-prop">exclude</a>。</p>
</div></div><!-- @@@property -->
<br/>
<!-- $$$target -->
<div class="qmlitem"><div class="qmlproto">
<div class="table"><table class="qmlname">
<tr valign="top" class="odd" id="target-prop">
<td class="tblQmlPropNode"><p>
<a name="target-prop"></a><span class="name">target</span> : <span class="type">Object</span></p></td></tr>
</table></div>
</div><div class="qmldoc"><p>These properties determine the items and their properties that are affected by this action.</p>
<p>The details of how these properties are interpreted in different situations is covered in the <a href="qml-qtquick-propertyanimation.html#properties-prop">corresponding</a> <a href="qtquick-animation-example.html#propertyanimation">PropertyAnimation</a> documentation.</p>
<p><b>请参考 </b><a href="qml-qtquick-propertyaction.html#exclude-prop">exclude</a>。</p>
</div></div><!-- @@@target -->
<br/>
<!-- $$$targets -->
<div class="qmlitem"><div class="qmlproto">
<div class="table"><table class="qmlname">
<tr valign="top" class="odd" id="targets-prop">
<td class="tblQmlPropNode"><p>
<a name="targets-prop"></a><span class="name">targets</span> : <span class="type"><a href="../qtqml/qml-list.html">list</a></span>&lt;<span class="type">Object</span>&gt;</p></td></tr>
</table></div>
</div><div class="qmldoc"><p>These properties determine the items and their properties that are affected by this action.</p>
<p>The details of how these properties are interpreted in different situations is covered in the <a href="qml-qtquick-propertyanimation.html#properties-prop">corresponding</a> <a href="qtquick-animation-example.html#propertyanimation">PropertyAnimation</a> documentation.</p>
<p><b>请参考 </b><a href="qml-qtquick-propertyaction.html#exclude-prop">exclude</a>。</p>
</div></div><!-- @@@targets -->
<br/>
<!-- $$$value -->
<div class="qmlitem"><div class="qmlproto">
<div class="table"><table class="qmlname">
<tr valign="top" class="odd" id="value-prop">
<td class="tblQmlPropNode"><p>
<a name="value-prop"></a><span class="name">value</span> : <span class="type">any</span></p></td></tr>
</table></div>
</div><div class="qmldoc"><p>This property holds the value to be set on the property.</p>
<p>If the <a href="qml-qtquick-propertyaction.html">PropertyAction</a> is defined within a <a href="qmlexampletoggleswitch.html#transition">Transition</a> or <a href="qml-qtquick-behavior.html">Behavior</a>, this value defaults to the value defined in the end state of the <a href="qmlexampletoggleswitch.html#transition">Transition</a>, or the value of the property change that triggered the <a href="qml-qtquick-behavior.html">Behavior</a>.</p>
</div></div><!-- @@@value -->
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